1. Field of the Invention
The invention relates to a suspension unit for optical devices, and in particular, to a suspension unit for mobile mounting of optical devices, such as cameras and video cameras.
2. Related Art
A triaxial gyroscopic stabilizer for movie or television cameras is known (U.S. Pat. No. 6,354,750), which comprises a platform on which a camera is mounted on, outer and middle frames of the suspension unit, with the orthogonal in a midposition axes of rotation, intersecting in one point, rotating drives of the frames and a platform, all connected to a control signal output.
Another triaxial gyroscopic stabilizer for movie or television camera is taught by (U.S.Pat. No. 5,868,031). The suspension unit of the gyroscopic stabilizer of the '031 patent includes a platform on which a camera is mounted, outer and middle frames of the suspension unit, with orthogonal midpositioned axes of rotation, intersecting in one point, rotating drives of the frames and a platform, connected to a control signal output. The outer frame construction of this the suspension unit is, however, asymmetrical in relation to the axis of its rotation and the rotating drive of the middle frame is located in a rear side of the camera. Both features of which create disadvantages in design. These features cause the center of mass of the outer frame displaced in relation to the axis of its rotation. When moving at high speeds, the suspension unit, unbalanced moments about axis of rotation of the frame are created, which causes errors in angular position of the platform in relation to the set control signal position, and degrade shot material quality.
Asymmetrical construction of the outer and middle frames of the suspension unit about the axis of the outer frame also causes aerodynamic asymmetry of the suspension unit with the camera in relation to this axis. Wind loading during shooting outdoors when mounted on a car or boat in motion, for example, also causes increasing aerodynamic torsional moment and increasing errors of the platform angular position, which also reduces image capture quality.
Moreover, in this prior art device, a middle axis of rotation of the suspension unit drives rotation of the middle frame, which is structurally placed behind the camera. This limits the longitudinal size of the camera with a lens when on the platform. It further complicates access to the camera and a cassette at service, narrows technical facilities of the suspension unit, and does not allow the use of wide line or long-focus lenses or other optical devices set in front of the lens of the camera (i.e., sun blends, a compendium and other).
A need therefore exists for increasing of the cameras angular position by reducing torsional moments generated by the suspension unit and expanding technical facilities of the suspension unit by improving operating features. A further need exists for a suspension unit having a symmetrical structural design of the outer and middle frames of the suspension unit and further locating the structural elements of the suspension unit such that they do not limit the longitudinal size of the camera with the lens when mounted on a platform.